There is known a toothbrush called an electric toothbrush, an ion toothbrush or an electronic toothbrush. This toothbrush is adapted to remove plague with potential gradient by allowing a weak current to flow through the body of a user to between a holder and a portion inserted into the user's mouth.
An electric toothbrush having such a function is disclosed in Japanese Patent No. 2560025. This electric toothbrush includes a shaft reciprocatingly driven in an axial direction thereof, a brush body attached to a tip end of the shaft and a terminal plate connected to an electric power source. The electric toothbrush is designed to supply electricity to the brush body through the shaft by bringing the terminal plate into contact with the shaft.
However, since the shaft makes sliding contact with the terminal plate during the course of reciprocating movement thereof, the shaft may be flexed when a brush of the brush body is pressed against the teeth or may be shaken when it makes reciprocating movement in an axial direction. This may change an electrical resistance in a sliding contact point between the shaft and the terminal plate, thereby posing a problem in that a great variation occurs in the electric current supplied.